However, both of these two schemes ( and almost all existing non-malleable commitment schemes) are subjected to the same constraint: the commitment phase and decommit phase cannot overlap in time. 然而,上述两方案(以及几乎所有已知的不可延展承诺方案)都存在一个共同的限制:承诺阶段和打开阶段在时间上不可重叠。